From: Nande, Central Africa
Source: Nande (D.R. Congo, Uganda) oral-tradition proverb (Abalibabiri bakikanayaesya nzwiri syangina minyera wangwe); documented in "A Collection of 100 Nande Proverbs and Wise Sayings" (afriprov.tangaza.ac.ke) — leopard entry
The source explains it: a people united can never be defeated
. The wording of the meaning is ours.